Study On Static Fracture Guidance Test Using Static Cracking Agent

The static Crack agent,also known as the sound-free Cracking agent,is a granular material with high expansion property.Static crushing technology has the advantages of no vibration,no harmful gas,no noise,no flying and no dust etc..When the static Cracking agent is used in the engineering application,the static fracture mode should be carried out because of the engineering requirements to avoid the special or more difficult position.According to the principle of fracture mechanics,the expansion pressure is concentrated in a section,which is the most easy to appear,and the fracture surface is rapidly developed along this direction.This paper attempts to use static fracture guidance method to carry out the rupture test of concrete components,and compare the static failure rules of concrete components with two different guiding devices,and explore the better scheme of static cracking of concrete members under guidance device.The expansion test of static cracking agent under different ambient temperature and water agent ratio is carried out.The ambient temperature is 10,15,20,respectively,and the water agent ratio is 0.26,0.28 and 0.30,respectively.The test results show that when the ambient temperature is 15 and the water agent ratio is 0.28,the static crushing agent reaches the maximum volume expansion rate,which is 4.02.The test uses the C40 strength element concrete component as the test object,which are the single hole and the three kinds of double hole concrete members with different hole distance respectively.For the analysis of guide block in the static crack during propagation,strain and impact fracture morphology of concrete,the steel tube guide device and a built-in steel sheet,comparative analysis of propagation law and strain changes of two kinds of block crack guiding device of concrete.Experimental results show that the directional pipe guiding device with built-in steel plate on concrete static fragmentation has better effect due to rupture;steel pipe guiding device has a stronger binding effect,block the crack initiation time than the built-in steel sheet concrete block the initiation time of night.The guiding steel tube has better guiding and cutting effect for the static fracture test,and the steel plate is suitable for the crushing of the test block.The test results provide an experimental basis for the application of static fracture guidance technology in concrete components.